const m = new Map([
  ["one", 1],
  ["two", 2],
]);
// k = one, v = 1
// k = two, v = 2
for (let [k, v] of m) console.log(`k = ${k}, v = ${v}`);
// one two
for (let [k] of m) console.log(k);
// 1 2
for (let [, v] of m) console.log(v);
